Here in NYC I am around many, many, latinos, and many of them consider themselves Black.
Many who claim to be not Black nor white, think that you'll avoid the trappings of racism. However, racism is simple, yet made complex for political purposes. IF YOU HAVE ANY HINT OF MELANIN? YOU ARE CONSIDERED BLACK according to white supremacist theory.
So yeah, you can call yourself mestizo, but once a NYC cop puts a gun in your nose, then calling you the Nword, you'll know what time it is. Better yet, go down south and attend a MAGA rally, then see what they think of you.